U.S. patent application number 12/641930 was filed with the patent office on 2010-07-01 for oil pan.
This patent application is currently assigned to DAIKYONISHIKAWA CORPORATION. Invention is credited to Satoshi ENOKIDA.
Application Number | 20100162988 12/641930 |
Document ID | / |
Family ID | 42221138 |
Filed Date | 2010-07-01 |
United States Patent
Application |
20100162988 |
Kind Code |
A1 |
ENOKIDA; Satoshi |
July 1, 2010 |
OIL PAN
Abstract
An oil pan made of resin includes an oil reservoir. The oil
reservoir includes a bottom wall and a peripheral wall rising from
a periphery of the bottom wall and having an opening at a top of
the oil reservoir. A rib is provided in the oil reservoir.
Inventors: |
ENOKIDA; Satoshi;
(Hiroshima, JP) |
Correspondence
Address: |
NIXON PEABODY, LLP
401 9TH STREET, NW, SUITE 900
WASHINGTON
DC
20004-2128
US
|
Assignee: |
DAIKYONISHIKAWA CORPORATION
Hiroshima
JP
|
Family ID: |
42221138 |
Appl. No.: |
12/641930 |
Filed: |
December 18, 2009 |
Current U.S.
Class: |
123/195C ;
123/198E |
Current CPC
Class: |
F01M 2011/0091 20130101;
F01M 2011/007 20130101; F01M 2011/002 20130101; F01M 11/0004
20130101; F01M 2011/0087 20130101 |
Class at
Publication: |
123/195.C ;
123/198.E |
International
Class: |
F01M 11/03 20060101
F01M011/03; F02F 7/00 20060101 F02F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 26, 2008 |
JP |
2008-332952 |
Jan 26, 2009 |
JP |
2009-014228 |
Jan 27, 2009 |
JP |
2009-015467 |
Claims
1. An oil pan made of resin, comprising: an oil reservoir including
a bottom wall and a peripheral wall rising from a periphery of the
bottom wall and having an opening at a top of the oil reservoir;
and a rib provided in the oil reservoir, wherein the rib extends
across the opening in plan view to join portions of the peripheral
wall which are separated from each other along a periphery of the
peripheral wall.
2. The oil pan of claim 1, further comprising a fastening portion
configured to fasten the oil pan and located in a portion of the
peripheral wall near the opening of the oil reservoir, wherein the
rib extends from a portion near the fastening portion.
3. The oil pan of claim 2, further comprising multiple ones of the
fastening portion, wherein the multiple ones of the fastening
portion are spaced apart from each other along the periphery of the
peripheral wall, and the rib joins portions near the multiple ones
of the fastening portion.
4. The oil pan of claim 3, further comprising first, second, and
third ribs joining portions near the multiple ones of the fastening
portion, and the first, second, and third ribs intersect each
other.
5. The oil pan of claim 1, further comprising multiple ones of the
rib, wherein the multiple ones of the rib intersect each other to
form at least one triangle in plan view.
6. The oil pan of claim 1, wherein the rib is continuous to the
bottom wall of the oil reservoir.
7. An oil pan, comprising a first part and a second part which are
made of resin and are formed as one piece, wherein the first part
includes a first rib, and the first rib is joined to the second
part.
8. The oil pan of claim 7, wherein the second part includes a
second rib, and the second rib is joined to the first part.
9. The oil pan of claim 8, comprising an oil strainer including a
filter element for filtering oil, and a filter-element housing
configured to house the filter element and having a suction port
for sucking oil and a discharge port for discharging oil which has
passed through the filter element, wherein the filter-element
housing includes the first rib and the second rib.
10. The oil pan of claim 7, wherein the first part has a fastening
portion configured to fasten the oil pan, and the first rib extends
from a portion near the fastening portion.
11. The oil pan of claim 7, wherein the first part forms an upper
portion of the oil pan, the second part forms a portion of the oil
pan including a bottom wall of the oil pan, and the first rib
extends vertically, and is joined to a bottom wall of the second
part.
12. An oil pan made of resin, comprising: an oil reservoir
including a bottom wall and a peripheral wall rising from a
periphery of the bottom wall and having an opening at a top of the
oil reservoir; and a rib provided in the oil reservoir, wherein the
rib divides an inside of the oil reservoir into a main chamber
having a suction port for sucking oil and a sub-chamber.
13. The oil pan of claim 12, wherein the rib has a through hole
configured to establish communication between the main chamber and
the sub-chamber.
14. The oil pan of claim 12, wherein the oil pan includes a first
part and a second part which are formed as one piece, the rib is
provided in each of the first part and the second part, and a gap
for establishing communication between the main chamber and the
sub-chamber is formed between the rib of the first part and the rib
of the second part.
15. The oil pan of claim 12, further comprising an oil strainer
provided in the main chamber, wherein the oil strainer includes a
filter element and a filter-element housing configured to house the
filter element, and the filter-element housing is constituted by
the rib.
16. The oil pan of claim 12, further comprising an oil strainer in
addition to the oil reservoir, and the oil strainer has a fixing
portion to be fixed to the rib.
17. The oil pan of claim 12, wherein the main chamber has a bottom
including an outer wall and an inner wall.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to oil pans made of
resin.
[0003] 2. Background Art
[0004] Conventional power units such as engines and automatic
transmissions are provided with oil pans for temporarily reserving
oil circulated in the power units (see, for example, Japanese
Patent Publications Nos. 2-264109 and 2006-283617). An oil pan
described in Japanese Patent Publication No. 2-264109 includes an
oil reservoir having a bottom wall and a peripheral wall rising
from the periphery of the bottom wall. An opening through which oil
circulated in a power unit flows into the oil reservoir is formed
at the top of the oil reservoir. A plurality of ribs and a
fastening portion fastened to the power unit are provided in the
oil reservoir, and are located closer to the outside than the
opening of the oil reservoir.
[0005] An oil pan described in Japanese Patent Publication No.
2006-283617 is formed out of a resin material, and includes an oil
reservoir having an opening located in an upper portion
thereof.
[0006] Further, in an oil pan described in Japanese Patent
Publication No. 2003-222012, an oil pan separator is provided in
the oil pan to divide an oil reservoir into a main chamber and a
sub-chamber such that oil which has circulated in the power unit
and returned to the oil reservoir flows into the main chamber
(where this oil will be referred to as return oil hereinafter), and
that the oil in the main chamber is sucked. With this
configuration, when the oil has high viscosity immediately after a
cold start, relatively warm return oil which has flown in the main
chamber circulates in each part of the power unit, and the
temperature of the oil in the main chamber is increased at an early
stage, thereby reducing the viscosity thereof. Consequently,
friction can be reduced, resulting in reduction of energy
consumption.
[0007] However, the oil pan of Japanese Patent Publication No.
2006-283617 is formed out of a resin material. Accordingly, the oil
pan can have a lighter weight than a steel-made oil pan, but might
have insufficient rigidity. In particular, the presence of the
opening in the oil reservoir considerably reduces rigidity.
Insufficient rigidity of the oil pan might cause each part of the
oil pan to easily vibrate with vibration of the power unit, thereby
producing noise. In addition, deformation and damage are likely to
occur upon application of external forces.
[0008] To solve the foregoing problems, a technique of providing a
rib for reinforcement as described in Japanese Patent Publication
No. 2-264109, is conceivable. However, this rib is provided outside
the opening of the oil reservoir, and thus the outer size of the
oil pan increases to an extent corresponding to the area of the
rib. In addition, even if the rib is provided outside the opening,
the opening is still large, and thus considerable reinforcement
cannot be expected.
[0009] Further, an oil strainer is provided in the oil pan, and
various components are provided outside the oil pan in some cases.
Thus, the shape of the oil pan needs to be adjusted so as to
prevent interference among these components. Moreover, the bottom
wall of the oil pan needs to be shaped to allow oil reserved
therein to be guided to a suction port of the oil strainer. For
these reasons, the shape of the oil pan tends to be
complicated.
[0010] If such an oil pan is to be formed as one piece made of
resin, as described in Japanese Patent Publication No. 2006-283617,
the resultant structure thereof is very complicated, and in some
cases, oil pan intended to have some shapes cannot be formed.
[0011] The oil pan of Japanese Patent Publication No. 2003-222012
includes an additional oil pan separator in order to divide the oil
reservoir into a main chamber and a sub-chamber. In this oil pan,
the number of parts constituting the oil pan increases, leading to
an increase in cost.
[0012] It is therefore a first object of the present disclosure is
to obtain a compact structure ensuring high rigidity by devising
ribs in a resin oil pan.
[0013] A second object of the present disclosure is to ensure high
rigidity while forming an oil pan of a resin material even when the
oil pan is intended to have a complicated shape.
[0014] A third object of the present disclosure is to reduce cost
by dividing an oil reservoir into a main chamber and a sub-chamber,
while enhancing rigidity of the resin oil pan without an increase
in the number of parts of the oil pan.
SUMMARY
[0015] To achieve the first object, in a first aspect of the
present disclosure, an oil pan made of resin includes: an oil
reservoir including a bottom wall and a peripheral wall rising from
a periphery of the bottom wall and having an opening at a top of
the oil reservoir; and a rib provided in the oil reservoir. The rib
extends across the opening in plan view to join portions of the
peripheral wall which are separated from each other along a
periphery of the peripheral wall.
[0016] In the first aspect, the rib extends across the opening in
plan view to join portions of the peripheral wall which are
separated from each other along a periphery of the peripheral wall.
Accordingly, the rib can sufficiently increase rigidity of portions
near the opening which otherwise decreases easily, and vibration of
each part of the oil pan can be reduced, thereby reducing noise.
Since the rib extends across the opening of the oil reservoir in
the manner described above, it is possible to dispose the rib by
effectively utilizing the space in the opening, while hardly
changing the outer shape of the oil pan. As a result, the oil pan
with the rib can be made compact with high rigidity achieved with
effective arrangement of the rib.
[0017] The oil pan may further include a fastening portion
configured to fasten the oil pan and located in a portion of the
peripheral wall near the opening of the oil reservoir, and the rib
may extend from a portion near the fastening portion.
[0018] In this case, since the rib extends from a portion near the
fastening portion, it is possible to increase strength of the
fastening portion by utilizing the rib.
[0019] The oil pan may further include multiple ones of the
fastening portion, wherein the multiple ones of the fastening
portion are spaced apart from each other along the periphery of the
peripheral wall, and the rib joins portions near the multiple ones
of the fastening portion.
[0020] In this case, the ribs join portions near the fastening
portions to each other, thereby further increasing strength of the
portions near the fastening portion.
[0021] The oil pan may further include first, second, and third
ribs joining portions near the multiple ones of the fastening
portion, and the first, second, and third ribs may intersect each
other.
[0022] In this case, the first, second, and third ribs joining
portions near the fastening portions intersect each other.
Accordingly, when a force is applied to the first rib, for example,
this force is distributed to the second rib and the third rib. As a
result, deformation and damage of the oil pan can be reduced.
[0023] The oil pan may further include multiple ones of the rib,
wherein the multiple ones of the rib intersect each other to form
at least one triangle in plan view.
[0024] In this case, since a plurality of ribs intersect each other
to form at least one triangle in plan view, the oil pan is less
likely to be deformed by a force applied to the side of the
peripheral wall, thereby further increasing rigidity.
[0025] The rib may be continuous to the bottom wall of the oil
reservoir.
[0026] In this case, since the rib is continuous to the bottom wall
of the oil reservoir, the rib can join the bottom wall and the
peripheral wall together, thereby further increasing rigidity of
the oil reservoir.
[0027] To achieve the second object, in a second aspect of the
present disclosure, an oil pan includes a first part and a second
part which are made of resin and are formed as one piece, wherein
the first part includes a first rib, and the first rib is joined to
the second part.
[0028] In this aspect, the first part and the second part can be
formed independently of each other. Accordingly, even if the shape
of the oil pan is intended to be complicated, the parts can be
easily formed as compared to a case where the parts are formed as
one piece, and thus good formability can be obtained. The first
part is reinforced by the first rib, and has its rigidity
increased. The first rib of the first part having the
thus-increased rigidity is joined to the second part, thereby
firmly uniting the first part and the second part. At the same
time, rigidity of the second part can also be enhanced, resulting
in that rigidity of the entire oil pan made of resin and intended
to have light weight can be increased.
[0029] The second part may include a second rib, and the second rib
may be joined to the first part.
[0030] In this case, the second rib can increase rigidity of the
second part, and joining of the second rib to the first part allows
the first part and the second part to be more firmly joined.
[0031] The oil pan may include an oil strainer including a filter
element for filtering oil, and a filter-element housing configured
to house the filter element and having a suction port for sucking
oil and a discharge port for discharging oil which has passed
through the filter element, wherein the filter-element housing
includes the first rib and the second rib.
[0032] In this case, the oil strainer can be provided as one piece
with the oil pan. In addition, since the filter-element housing of
the oil strainer is formed by utilizing the first rib and the
second rib, the structure of the oil pan can be simplified, and the
weight of the oil pan can be reduced, as compared to a case where
the filter-element housing is provided as an additional part.
[0033] The first part may have a fastening portion configured to
fasten the oil pan, and the first rib may extend from a portion
near the fastening portion.
[0034] In this case, since the first rib extends from a portion
near fastening portion, rigidity of the fastening portion can be
increased.
[0035] The first part may form an upper portion of the oil pan, the
second part may form a portion of the oil pan including a bottom
wall of the oil pan, and the first rib may extend vertically in a
vertical direction, and be joined to a bottom wall of the second
part.
[0036] In this case, since the first rib is joined to the bottom
wall of the second part, the bottom wall of the oil pan can be
reinforced.
[0037] To achieve the third object, in a third aspect of the
present disclosure, an oil pan made of resin includes: an oil
reservoir including a bottom wall and a peripheral wall rising from
a periphery of the bottom wall and having an opening at a top of
the oil reservoir; and a rib provided in the oil reservoir, wherein
the rib divides an inside of the oil reservoir into a main chamber
having a suction port for sucking oil and a sub-chamber.
[0038] In this case, the rib in the oil reservoir can increase
rigidity of the oil pan. In addition, since the rib divides the
inside of the oil reservoir into the main chamber and the
sub-chamber, it is unnecessary to provide an additional oil pan
separator. Accordingly, the number of components of the oil pan can
be reduced, thereby reducing cost.
[0039] The rib may have a through hole configured to establish
communication between the main chamber and the sub-chamber.
[0040] In this case, oil in the sub-chamber can flow into the main
chamber through the through hole of the rib. Accordingly, only
forming the through hole in the rib can easily obtain a structure
for establishing communication between the main chamber and the
sub-chamber.
[0041] The oil pan may include a first part and a second part which
are formed as one piece, the rib may be provided in each of the
first part and the second part, and a gap for establishing
communication between the main chamber and the sub-chamber may be
formed between the rib of the first part and the rib of the second
part.
[0042] In this case, since the oil pan is divided into the first
part and the second part, good formability can be obtained even if
the oil pan is intended to have a complicated shape. In addition,
since a gap for establishing communication between the main chamber
and the sub-chamber is formed between the rib of the first part and
the rib of the second part, a structure for establishing
communication between the main chamber and the sub-chamber can be
easily obtained.
[0043] The oil pan may further include an oil strainer provided in
the main chamber, wherein the oil strainer includes a filter
element and a filter-element housing configured to house the filter
element, and the filter-element housing is constituted by the
rib.
[0044] In this case, the oil strainer can be provided as one piece
with the oil pan. Since the filter-element housing of the oil
strainer is formed by utilizing the rib, the oil pan can have
lighter weight than in a case where the filter-element housing is
made of an additional part.
[0045] The oil pan may further include an oil strainer in addition
to the oil reservoir, and the oil strainer may have a fixing
portion to be fixed to the rib.
[0046] In this case, the oil strainer provided independently of the
oil reservoir can be fixed to the rib. That is, the rib can also be
used for fixing the oil strainer.
[0047] The main chamber may have a bottom including an outer wall
and an inner wall.
[0048] In this case, the bottom of the main chamber has a multiple
structure made of the outer wall and the inner wall, thereby
enhancing heat insulating properties. Accordingly, in particular,
oil in the main chamber is less likely to be cooled by cold outside
air in a cold state, and thus the temperature of oil sucked into
the power unit can be increased quickly, thereby reducing
viscosity. As a result, energy consumption can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is a perspective view of an oil pan according to a
first embodiment.
[0050] FIG. 2 is a view of the oil pan when viewed from the rear of
a vehicle.
[0051] FIG. 3 is a right-side view of the oil pan.
[0052] FIG. 4 is a plan view of the oil pan.
[0053] FIG. 5 is an exploded view of the oil pan.
[0054] FIG. 6 is a perspective view illustrating a cross-sectional
structure taken along line VI-VI in FIG. 4.
[0055] FIG. 7 is a bottom view of the oil pan.
[0056] FIG. 8 is a perspective view of a lower section.
[0057] FIG. 9 is a plan view of the lower section.
[0058] FIG. 10 is a bottom view of an upper section.
[0059] FIG. 11 is a perspective view illustrating a right portion
of the lower section and a filter element.
[0060] FIG. 12 is an enlarged view of a portion near an oil
strainer and corresponding to FIG. 6.
[0061] FIG. 13 is a plan view of the filter element.
[0062] FIG. 14 is a view of the filter element when viewed from an
engagement plate portion.
[0063] FIG. 15 is a plan view of main ribs and auxiliary ribs.
[0064] FIG. 16 is a cross-sectional view taken along line XVI-XVI
in FIG. 4.
[0065] FIG. 17 is a cross-sectional view taken along line XVII-XVII
in FIG. 4.
[0066] FIG. 18 is a view corresponding to FIG. 17 and illustrating
a first modified example.
[0067] FIG. 19 is a view corresponding to FIG. 17 and illustrating
a second modified example.
[0068] FIG. 20 is a view corresponding to FIG. 17 and illustrating
a third modified example.
[0069] FIG. 21 is an exploded perspective view of an oil pan
according to a fourth modified example.
[0070] FIG. 22 is a view corresponding to FIG. 16 and illustrating
a second embodiment.
[0071] FIG. 23 is a perspective view of portions of ribs near a
projection wall when viewed from below.
[0072] FIG. 24 is a perspective view of portions of ribs near the
projection wall when viewed from above.
DETAILED DESCRIPTION
[0073] Embodiments of the present disclosure will be described in
detail hereinafter with reference to the drawings. The following
embodiments are merely examples in nature, and are not intended to
limit the scope, applications, and use of the invention.
Embodiment 1
[0074] FIG. 1 illustrates an oil pan 1 according to a first
embodiment of the present invention. The oil pan 1 is intended to
be used in an engine (not shown) mounted on an engine compartment
at the front of an automobile, and is attached to the lower surface
of a cylinder block 100 of the engine, as illustrated in FIGS. 2
and 3. The engine mounted in the engine compartment is positioned
such that the crank shaft extends in the lateral direction of the
automobile.
[0075] In the embodiments, the front side of the automobile is
referred as the "front," the rear side of the automobile is
referred to as the "rear," the left side of the automobile is
referred as the "left," and the right side of the automobile is
referred as the "right," for simplicity.
[0076] The oil pan 1 includes: a recessed oil reservoir 4 formed by
a bottom wall 2 covering substantially the entire bottom surface of
the cylinder block 100 and a peripheral wall 3 rising from the
periphery of the bottom wall 2; first through fifth main ribs M1-M5
and first through ninth auxiliary ribs S1-S9 provided in the oil
reservoir 4 as illustrated in FIGS. 1 and 4; and an oil strainer 5
provided in the oil reservoir 4 in the same manner. As illustrated
in FIG. 5, the oil pan 1 is formed by a combination of three
members: an upper section (a first part) 10; a lower section (a
second part) 30; and a filter element 50 (shown in FIG. 6). The
upper and lower sections 10 and 30 are vertically disposed. As
illustrated in FIG. 1, an opening 6 is formed at the top of the oil
reservoir 4. Oil dropped from the cylinder block 100 flows into the
oil reservoir 4 through this opening 6. The internal space of the
oil reservoir 4 is divided into a main chamber P and a sub-chamber
Z as described below (see, FIG. 4).
[0077] Oil in the oil reservoir 4 is filtered when passing through
the oil strainer 5, and is sucked into an oil pump (not shown) of
the engine, and fed to each part of the engine to circulate
therein. Then, the oil returns to the oil reservoir 4, and passes
through the oil strainer 5 again. As illustrated in FIG. 6, the oil
strainer 5 includes the filter element 50, and a filter-element
housing 17 for housing the filter element 50.
[0078] As illustrated in FIGS. 2 and 3, the bottom wall 2 of the
oil reservoir 4 is long in the lateral direction of the automobile.
The bottom wall 2 has a downward protuberance 7. As illustrated in
FIG. 7, the protuberance 7 extends from the right end of the bottom
wall 2 across the middle of the bottom wall 2 in the lateral
direction. As also illustrated in FIG. 2, the left end of the
protuberance 7 is located at the right of the left end of the
bottom wall 2. As illustrated in FIG. 7, the left end of the
protuberance 7 projects toward the left at the middle thereof in
the front-to-rear direction.
[0079] As illustrated in FIG. 5, the protuberance 7 is included in
the lower section 30. The part of the bottom wall 2 except for the
protuberance 7 and the peripheral wall 3 are included in the upper
section 10. The lower section 30 and the upper section 10 are made
of resin. As illustrated in FIGS. 8 and 9, the lower section 30 is
open at the top thereof. A lower joining portion 31 to be welded to
the upper section 10 is formed at the top of the lower section 30.
The lower joining portion 31 extends from the top of the lower
section 30 to outside the protuberance 7, and is in the shape of an
annular plate along the entire periphery of the top of the lower
section 30.
[0080] On the other hand, as illustrated in FIG. 10, a through hole
11 matching with the top of the lower section 30 is formed in the
bottom of the upper section 10. An upper joining portion 12 to be
welded to the lower joining portion 31 of the lower section 30 is
formed around the through hole 11 of the upper section 10. The
upper joining portion 12 is in the shape of a plate extending along
the lower joining portion 31. The lower joining portion 31 and the
upper joining portion 12 can be welded together by, for example,
various welding techniques such as hot plate welding and vibration
welding. Since the lower joining portion 31 at the top of the lower
section 30 is in the shape of an annular plate along the entire
periphery and extending outward from the lower section 30, and has
its entire periphery joined to the upper joining portion 12, the
rigidity of the oil pan 1 as a whole can be increased.
[0081] As illustrated in FIG. 11, an element-fixing rib 32 to which
the filter element 50 is fixed is formed on a right portion of the
bottom wall of the lower section 30, and reinforces the bottom wall
of the lower section 30. The element-fixing rib 32 is in the shape
of a thick plate projecting upward from the bottom wall of the
lower section 30. The element-fixing rib 32 extends to the right
end at the front end of the bottom wall, then bends and extends
rearward, and then bends to the left, thereby forming an
approximate C-shape which is open at the left in plan view of FIG.
9. Since the element-fixing rib 32 bends in the manner described
above, the rigidity of the rib 32 itself can also be increased.
[0082] Oil in the oil reservoir 4 flows into space formed by the
element-fixing rib 32 through the opening at the left of the
element-fixing rib 32. Reference numeral 33 in FIG. 7 denotes a
groove formed by the element-fixing rib 32. In other words, the
element-fixing rib 32 is a hollow rib.
[0083] As illustrated in FIG. 11, the height of the element-fixing
rib 32 from the bottom wall increases toward the rear and toward
the right end. An upward projection 32a is fowled at the top of the
element-fixing rib 32. As illustrated in FIG. 12, this projection
32a is configured to be welded to the filter element 50 and the
upper section 10.
[0084] As illustrated in FIGS. 8 and 9, first through fifth lower
ribs L1-L5 projecting upward are formed on the bottom wall of the
lower section 30. The first lower rib L1 is connected to a rear
portion of the element-fixing rib 32, extends rearward, and then
bends to the left. The height of a left portion of the first lower
rib L1 gradually decreases toward the left end.
[0085] The second lower rib L2 is located at the left of the left
side of the first lower rib L1, and is spaced apart from the first
lower rib L1. The height of a right portion of the second lower rib
L2 gradually decreases toward the right end, whereas the height of
a left portion of the second lower rib L2 gradually decreases
toward the left end. In other words, the second lower rib L2 is
tapered.
[0086] The third lower rib L3 is located at the left of the left
side of the second lower rib L2, is spaced apart from the second
lower rib L2, and extends to the left front. The height of a right
portion of the third lower rib L3 gradually decreases toward the
right end. The left side of the third lower rib L3 is continuous to
the inner surface of the lower section 30. The fourth lower rib L4
is located in front of the third lower rib L3, and is spaced apart
from the third lower rib L3. The height of a right portion of the
fourth lower rib L4 gradually decreases toward the right end. The
left end of the fourth lower rib L4 is continuous to the inner
surface of the lower section 30.
[0087] The fifth lower rib L5 is located in front of the second
lower rib L2, is spaced apart from the second lower rib L2, and
extends to the right front. The heights of left and right portions
of the fifth lower rib L5 respectively decrease toward the both
ends thereof, as the second lower rib L2, i.e., the fifth lower rib
L5 is also tapered.
[0088] As illustrated in FIG. 13, the filter element 50 is made of
resin, and includes a plate-shape filter mesh 51 and an attaching
portion 52 provided on the periphery of the mesh 51. As illustrated
in FIG. 12, the filter element 50 is positioned such that the mesh
51 is substantially in parallel with the bottom wall of the lower
section 30.
[0089] As also illustrated in FIG. 11, the mesh 51 is approximately
rectangular to cover the top of the upper edge of the
element-fixing rib 32. A plurality of reinforcement portions 53
extending in the length and width directions are provided on the
mesh 51. As illustrated in FIG. 13, the attaching portion 52 has an
approximately C-shape which matches with the shape of the top of
the element-fixing rib 32 in plan view. As illustrated in FIGS. 11
and 14, the attaching portion 52 has an engagement plate portion 54
projecting downward to be engaged with a left rear portion of the
element-fixing rib 32. In addition, as illustrated in FIG. 12, an
inner projection 55 projecting downward and extending along the
periphery is formed on the inner periphery of the attaching portion
52, and an outer projection 56 projecting downward in the same
manner is formed on the outer periphery of the attaching portion
52. A groove 58 is formed between the inner projection 55 and the
outer projection 56. An annular projection 57 extending along the
entire periphery is formed on the periphery of the top of the mesh
51.
[0090] The tip (i.e., the lower end) of the inner projection 55 of
the filter element 50 is located closer to the inside than the
projection 32a at the top of the element-fixing rib 32 of the lower
section 30. The tip (i.e., the lower end) of the outer projection
56 of the filter element 50 is welded to the projection 32a of the
element-fixing rib 32 along the entire periphery. The space
enclosed by the filter element 50 and the element-fixing rib 32 is
an inflow room R1 into which oil flows in the oil strainer 5.
[0091] On the other hand, as illustrated in FIG. 1, an upper flange
13 extending outward from the oil reservoir 4 is formed on top of
the peripheral wall 3 which is the top of the upper section 10. As
also illustrated in FIG. 4, first through fourth front
bolt-insertion holes (fastening portions) Bf1-Bf4 through which
bolts (not shown) for fastening the oil pan 1 to the cylinder block
100 are inserted, are provided in a front portions of the upper
flange 13, and are spaced apart from each other in the
right-to-left direction. The first front bolt-insertion hole Bf1 is
located near the left end of the upper flange 13, and the second
through fourth front bolt-insertion holes Bf1-Bf4 are arranged in
this order toward the right.
[0092] First through fourth rear bolt-insertion holes (fastening
portions) Bb1-Bb4 are formed in a rear portion of the upper flange
13, and are spaced apart from each other in the right-to-left
direction. The first through fourth rear bolt-insertion holes
Bb1-Bb4 are arranged in the same manner as the first through fourth
front bolt-insertion holes Bf1-Bf4.
[0093] First and second left bolt-insertion holes (fastening
portions) B11 and B12 are provided in a left portion of the upper
flange 13, and are spaced apart from each other in the
front-to-rear direction. The first left bolt-insertion hole B11 is
located toward the front side of the upper flange 13, and the
second left bolt-insertion hole B12 is located toward the rear side
of the upper flange 13.
[0094] First and second right bolt-insertion holes (fastening
portions) Br1 and Br2 are formed in a right portion of the upper
flange 13, and are spaced apart from each other in the same manner
as the left bolt-insertion holes B11 and B12. Bolt-interference
prevention portions 3a, 3a, . . . which are recessed toward the
inside of the oil reservoir 4, are formed in portions of the
peripheral wall 3 associated with the bolt insertion holes Bf1-Bf4,
Bb1-Bb4, B11, B12, Br1, and Br2.
[0095] Side flanges 14 fastened to a casing 101 (indicated by
virtual lines only in FIG. 4) of a transmission are formed in a
left portion of the peripheral wall 3 at the left of the upper
section 10. The side flanges 14 respectively project from the front
and rear side of the peripheral wall 3. As illustrated in FIG. 1,
three bolt-insertion holes 14a, 14a, and 14a through which bolts
(not shown) are screwed into bolt holes formed in the casing 101 of
the transmission, are formed in each of the side flanges 14, and
are spaced apart from each other in the front-to-rear
direction.
[0096] The first through fifth main ribs M1-M5 and the first
through ninth auxiliary ribs S1-S9 are arranged in the upper
section 10. In FIG. 15, the first through fifth main ribs M1-M5 are
indicated by solid lines, and the first through ninth auxiliary
ribs S1-S9 are indicated by hollow lines.
[0097] As illustrated in FIG. 15, the first main rib M1 extends
straight from a portion near the second front bolt-insertion hole
Bf2 to a portion near the second rear bolt-insertion hole Bb2 to
join the fastening portions Bf2 and Bb2 to each other, and is
located closer to the center of the through hole 11 than the left
end of the through hole 11 of the upper section 10. The second main
rib M2 extends straight from a portion near the third front
bolt-insertion hole Bf3 to a portion near the third rear
bolt-insertion hole Bb3.
[0098] The third main rib M3 extends straight from a portion near
the fourth front bolt-insertion hole Bf4 to a portion near the
fourth rear bolt-insertion hole Bb4. The first through third main
ribs M1-M3 are substantially in parallel with each other.
[0099] The fourth main rib M4 extends straight from a portion near
the first left bolt-insertion hole B11 to a portion near the second
right bolt-insertion hole Br2. As illustrated in FIG. 5, a lower
portion of the fourth main rib M4 extends toward the bottom wall of
the lower section 30. The fourth main rib M4 extends in a direction
along which the first and second lower ribs L1 and L2 (shown in
FIG. 9) of the lower section 30 extend, and is located directly
above the first and second lower ribs L1 and L2. Specifically, the
lower portion of the fourth main rib M4 has V-shaped notches 20 and
20 (see, FIGS. 5 and 10) in which the first and second lower ribs
L1 and L2 shown in FIG. 8 are located. As illustrated in FIG. 16,
gaps T1 and T1 through which oil can be distributed are
respectively formed between the notches 20 and 20 and the first and
second lower ribs L1 and L2. The sizes of the gaps T1 preferably
increase toward the tops of the first and second lower ribs L1 and
L2 in order to cause warm oil in the oil pan 1 to flow into the
main chamber P in the manner which will be described later. The
sizes of the gaps T1 may increase toward the bottoms of the first
and second lower ribs L1 and L2.
[0100] As illustrated in FIG. 15, the fifth main rib M5 extends
substantially straight from a portion near the second left
bolt-insertion hole B12 to a portion near the fist right
bolt-insertion hole Br1.
[0101] The second main rib M2, the fourth main rib M4, and the
fifth main rib M5 intersect at a point A. The point A is located at
the middle of the second main rib M2 in the front-to-rear
direction. The fourth main rib M4 and the second main rib M2 do not
intersect at right angles, and the fifth main rib M5 and the second
main rib M2 do not intersect at right angles, either. Further, the
fourth main rib M4 and the fifth main rib M5 do not intersect at
right angles. Alternatively, the second, fourth, and fifth main
ribs M2, M4, and M5 may intersect each other at right angles.
[0102] The fourth main rib M4 intersects the first main rib M1 and
the third main rib M3 at points B and E, respectively. The fifth
main rib M5 intersects the first main rib M1 and the third main rib
M3 at points C and D, respectively. The points B-E are located
within the through hole 11 of the upper section 10 in plan view.
The bottoms of the first main rib M1, the fourth main rib M4, and
the fifth main rib M5 are continuous to portions of the upper
section 10 constituting the bottom wall 2. The ribs M1, M4, and M5
join the peripheral wall 3 and the bottom wall 2 to each other. The
first through fifth main ribs M1-M5 extend across the opening 6 to
join separate portions of the peripheral wall 3 to each other.
[0103] The first auxiliary rib S1 extends straight from a portion
near the first front bolt-insertion hole Bf1 to the point B. A
lower portion of the first auxiliary rib S1 extends to the bottom
wall of the lower section 30. The third lower rib L3 of the lower
section 30 illustrated in FIG. 8 is located directly under the
first auxiliary rib S1. A portion of the third lower rib L3 is
located under the fourth main rib M4. A notch 21 (see, FIG. 10) in
which the third lower rib L3 is located, is formed in lower
portions of the first auxiliary rib S1 and the fourth main rib M4.
As illustrated in FIG. 16, a gap T2 through which oil can be
distributed is formed between the notch 21 and the third lower rib
L3. The size of the gap T2 preferably increases toward the top of
the third lower rib L3, as described above. Alternatively, the size
of the gap T2 may increase toward the bottom of the third lower rib
L3.
[0104] As illustrated in FIG. 15, the second auxiliary rib S2
extends straight from a portion near the fourth front
bolt-insertion hole Bf4 to the point B, and intersects the second
main rib M2 at its intermediate portion, which is a point F. A
lower portion of the second auxiliary rib S2 extends to the bottom
wall of the lower section 30. The second auxiliary rib 52 extends
in a direction along which the fifth lower rib L5 of the lower
section 30 shown in FIG. 9 extends, and is located immediately
above the fifth lower rib L5. A V-shaped notch 22 (see, FIGS. 6 and
10) in which the fifth lower rib L5 shown in FIG. 9 is located, is
formed in a lower portion of the second auxiliary rib S2. As
illustrated in FIG. 6, a gap T3 through which oil can be
distributed is formed between the notch 22 and the fifth lower rib
L5. The size of the gap T3 preferably increases toward the top of
the fifth lower rib L5, as described above. Alternatively, the size
of the gap T3 may increase toward the bottom of the fifth lower rib
L5.
[0105] As illustrated in FIG. 15, the third auxiliary rib S3
extends straight from a portion near the second front
bolt-insertion hole Bf2 to the point F. The fourth auxiliary rib S4
extends straight from a portion near the fourth front
bolt-insertion hole Bf4 to the point A. The fifth auxiliary rib S5
extends straight from a portion near the fourth rear bolt-insertion
hole Bb4 to the point A. The sixth auxiliary rib S6 extends
straight from a portion near the fourth rear bolt-insertion hole
Bb4 to the point C. The sixth auxiliary rib S6 intersects the
second main rib M2 at its intermediate portion, which is a point G.
The seventh auxiliary rib S7 extends from a portion near the second
rear bolt-insertion hole Bb1 to the point G. The eighth auxiliary
rib S8 extends straight from a portion near the first rear
bolt-insertion hole Bb1 to the point C. The ninth auxiliary rib S9
extends to the right from a portion between the first and second
left bolt-insertion holes B11 and B12, and then is divided into two
portions which respectively extend to the point B and the point C.
The point at which the ninth auxiliary rib S9 is divided is a point
H. The bottoms of the first auxiliary rib S1, the third auxiliary
rib S3, the sixth auxiliary rib S6, the seventh auxiliary rib S7,
the eighth auxiliary rib S8, and the ninth auxiliary rib S9 are
continuous to portions of the upper section 10 constituting the
bottom wall 2. The first through fifth main ribs M1-M5 and the
first through ninth auxiliary ribs S1-S9 are upright ribs extending
substantially vertically, and are formed as one piece.
[0106] The first through fifth main ribs M1-M5 and the first
through ninth auxiliary ribs S1-S9 extending as described above
intersect each other to form triangles in plan view. For example,
the first main rib M1, the sixth auxiliary rib S6, and the seventh
auxiliary rib S7 form a triangle. The first left bolt-insertion
hole B11, the second left bolt-insertion hole B12, and the point A
also form a triangle. In this manner, intersections between the
fastening portions and the ribs form triangles, thereby achieving a
strong structure against external forces.
[0107] As illustrated in FIG. 4, return space W is defined, and
sandwiched, by the first main rib M1 and the first auxiliary rib
S1. A return pipe 102 (indicated by virtual lines in FIGS. 1 and 4)
to which return oil from the cylinder block 100 is discharged, is
located between the first main rib M1 and the first auxiliary rib
S1, i.e., in the return space W, in plan view. With this
configuration, most part of circulated oil drops into the return
space W. Oil also drops from portions of the bottom surface of the
cylinder block 100 except for the return pipe 102.
[0108] As illustrated in FIG. 4, the upper section 10 is provided
with a cover 16 covering the top of the filter element 50 fixed to
the element-fixing rib 32. As illustrated in FIG. 12, the cover 16
and the element-fixing rib 32 constitute the filter-element housing
17 for housing the filter element 50.
[0109] As illustrated in FIG. 4, the cover 16 is constituted by
portions of the third main rib M3, the fifth main rib M5, and the
fourth auxiliary rib S4, and is located in space surrounded by the
third main rib M3, the fourth main rib M4, and the fourth auxiliary
rib S4. The cover 16 has a rectangle shape substantially the same
as the shape of the filter element 50 in plan view, and as
illustrated in FIG. 12, the periphery of the cover 16 is continuous
to intermediate portions, in the vertical direction, of the side
surfaces of the ribs M3 and S4. In addition, as illustrated in FIG.
4, the fifth main rib M5 is located at an approximate center of the
cover 16.
[0110] A discharge pipe 15 for discharging oil which has passed
through the filter element 50 is formed in a front portion of the
cover 16 to project upward. The discharge pipe 15 is located in the
space surrounded by the third main rib M3, the fifth main rib M5,
and the fourth auxiliary rib S4. The opening at the upper end of
the discharge pipe 15 serves as a discharge port 15a through which
oil from the filter element 50 is discharged.
[0111] As illustrated in FIG. 12, an engagement recess 16a with
which the outer periphery of the filter element 50 is engaged, is
formed in the bottoms of the third main rib M3, the fifth main rib
M5, and the fourth auxiliary rib S4 at a position associated with
the outer periphery of the filter element 50 along the entire
periphery. A projecting welding portion 16b to be welded to the
projection 32a of the element-fixing rib 32 of the lower section 30
is formed along the entire periphery, and is located closer to the
outer periphery than the engagement recess 16a. A contact portion
16c to be in contact with a portion closer to the outer periphery
than the projection 32a at the top of the element-fixing rib 32 is
formed along the entire periphery, and is located closer to the
outer periphery than the welding portion 16b.
[0112] The space surrounded by the cover 16 and the filter element
50 serves as an outflow room R2 for oil in the oil strainer 5. The
cover 16 can firmly join the third main rib M3, the fifth main rib
M5, and the fourth auxiliary rib S4 together.
[0113] As illustrated in FIG. 1, the top of the discharge pipe 15
is located near the top of the upper section 10. The discharge port
15a of the discharge pipe 15 is connected to an oil suction hole
(not shown) formed in the bottom surface of the cylinder block 100
with the oil pan 1 attached to the cylinder block 100. A suction
hole 5a (indicated by broken lines in FIGS. 4 and 6) of the oil
strainer 5 is constituted by an opening portion of the
element-fixing rib 32.
[0114] The fourth main rib M4 and the second auxiliary rib 52 of
the upper section 10 and the lower ribs L1-L5 of the lower section
30 divide the inside of the oil reservoir 4 into the main chamber P
and the sub-chamber Z. The main chamber P is the space surrounded
by the fourth main rib M4, the second auxiliary rib S2, and the
lower ribs L1-L5. The suction hole 5a of the oil strainer 5 faces
the inside of the main chamber P. The volume of the main chamber P
is preferably smaller than that of the sub-chamber 4 but may be
equal to that of the sub-chamber Z. Alternatively, the volume of
the sub-chamber Z may be smaller than that of the main chamber
P.
[0115] The first main rib M1, the first auxiliary rib S1, and the
second auxiliary rib S2 of the upper section 10 has a guide part 60
for guiding return oil which has returned to the oil reservoir 4
through the return pipe 102 to the main chamber P. As also
illustrated in FIG. 17, the guide part 60 includes: a tube portion
61 extending substantially in the right-to-left direction to join
the first main rib M1 and the second auxiliary rib S2 to each
other; and a guide plate portion 62 continuous to the bottom wall
of the tube portion 61 and extending to the first auxiliary rib S1.
The tube portion 61 is formed as one piece with the first main rib
M1 and the second auxiliary rib S2. The guide plate portion 62 is
formed as one piece with the first main rib M1 and the first
auxiliary rib S1.
[0116] The tube portion 61 is configured to form a main oil
passageway Q for allowing substantially the entire amount of return
oil which has flown into the return space W to flow into the main
chamber P. The left end of the tube portion 61 communicates with
the return space W between the first main rib M1 and the first
auxiliary rib S1, and the right end thereof communicates with the
main chamber P. Specifically, an opening 24 facing the return space
W is formed in an intermediate portion, in the vertical direction,
of the first main rib M1. The left end of the tube portion 61 is
connected to the opening 24. An opening 23 facing the main chamber
P is formed in an intermediate portion, in the vertical direction,
of the second auxiliary rib S2. The right end of the tube portion
61 is connected to the opening 23.
[0117] As also illustrated in FIG. 4, the guide plate portion 62 is
used for guiding return oil to the main oil passageway Q of the
tube portion 61 by closing the through hole 11 between the first
main rib M1 and the first auxiliary rib S1, and thereby preventing
the return oil from flowing downward through the through hole
11.
[0118] The guide part 60 described above enables oil circulated in
the engine to be sucked directly into the oil strainer 5. The guide
part 60 allows the first main rib M1, the first auxiliary rib S1,
and the second auxiliary rib S2 to be joined together, thereby
obtaining high rigidity.
[0119] A process of fabricating the oil pan 1 with the foregoing
configuration will now be described. First, a resin material is
injection molded to obtain an upper section 10, a lower section 30,
and a filter element 50. Then, the filter element 50 is mounted on
the upper section 10. Specifically, as illustrated in FIG. 12, an
annular projection 57 of the filter element 50 is fitted into an
engagement recess 16a of a cover 16. Thereafter, an outer
projection 56 of the filter element 50 and a welding portion 16b of
the cover 16 are brought into contact with a projection 32a of a
filter-fixing rib 32.
[0120] Next, a lower joining portion 31 of the lower section 30 and
an upper joining portion 12 of the upper section 10 are welded
together by, for example, vibration welding. At this time, the
outer projection 56 of the filter element 50 and the welding
portion 16b of the cover 16 are welded to the projection 32a of the
filter-fixing rib 32 at a time in the same manner. In this manner,
a third main rib M3 and a fourth auxiliary rib S4 of the upper
section 10 are joined to the element-fixing rib 32 of the lower
section 30, thereby firmly joining the upper section 10 and the
lower section 30 to each other.
[0121] To attach the thus-obtained oil pan 1 to a cylinder block
100, bolts are inserted into bolt-insertion holes Bf1-Bf4, Bb1-Bb4,
B11, B12, Br1, and Br2, and are tightened. In this manner, an oil
discharge pipe 15 of the oil pan 1 is connected to an oil suction
hole of the cylinder block 100.
[0122] Then, when the engine starts to initiate operation of an oil
pump, a negative pressure is created in the oil discharge pipe 15
to cause oil in a main chamber P to be sucked into an inflow room
R1 through a suction hole 5a of an oil strainer 5. The oil in the
inflow room R1 is filtered while passing through a mesh 51 of the
filter element 50, and then flows into an outflow room R2. The oil
in the outflow room R2 flows upward through the discharge pipe 15
to be supplied to each part of the engine.
[0123] A large part of oil circulated in parts of the engine, flows
into return space W in an oil reservoir 4 of the oil pan 1 through
a return pipe 102. This return oil is guided from the left end of a
tube portion 61 to a main oil passageway Q by a guide plate portion
62 of a guide part 60, as indicated by white arrows in FIG. 17. Oil
which has passed through the main oil passageway Q flows into a
main chamber P from the right end of the tube portion 61. The
return oil is warmer than other oil, and this relatively warm oil
can be sucked into the oil strainer 5 from the main chamber P.
Accordingly, the temperature of oil can be increased quickly, and
thus a viscosity appropriate for lubricating each part of the
engine can be obtained to reduce rotational resistance of the
engine, resulting in enhancing fuel efficiency.
[0124] Return oil also flows into the main chamber P through the
gaps T1 and T2 shown in FIG. 16 and the gap T3 shown in FIG. 6.
However, because of high viscosity of oil in a cold state, the
amounts of return oil flowing through the gaps T1, T2, and T3 are
small. The amount of oil flowing through the gaps T1, T2, and T3
increases, as the oil viscosity decreases. The sizes of the gaps
T1, T2, and T3 may differ from each other, or may be identical.
[0125] As illustrated in FIG. 15, all the points A through H as
intersections of the first through fifth main ribs M1-M5 and the
first through ninth auxiliary ribs S1-S9 are located within the
through hole 11 of the upper section 10 in plan view. With this
configuration, oil dropped in a portion between the fifth main rib
M5 and the ninth auxiliary rib S9 and oil dropped in a portion
between the fifth main rib M5 and the eighth auxiliary rib S8, for
example, are caused to flow into the lower section 30 through the
through hole 11, and are sucked into the oil strainer 5.
[0126] In addition, since the first through fifth main ribs M1-M5
join separate portions of the peripheral wall 3 of the oil
reservoir 4 together, and extend across the opening 6 of the oil
reservoir 4, the ribs M1-M5 can sufficiently increase rigidity of
portions near the opening 6, which otherwise decreases easily.
Further, the connection of the first through ninth auxiliary ribs
S1-S9 to the first through fifth main ribs M1-M5 can provide higher
rigidity. Accordingly, when an obstacle such as flying stones and
curbs hits the oil pan 1 in driving of the automobile, deformation
and damage of the oil pan 1 can be reduced. During rotation of the
engine, vibration of the cylinder block 100 is transmitted to the
oil pan 1. In this situation, the presence of the first through
fifth main ribs M I-M5 and the first through ninth auxiliary ribs
S1-S9 in the oil pan 1 can reduce vibration of the peripheral wall
3 and the bottom wall 2, thereby reducing noise. In addition, since
the first through fifth main ribs M1-M5 and the first through ninth
auxiliary ribs S1-S9 are joined to each other, vibration of these
ribs M1-M5 and S1-S9 can be reduced.
[0127] Moreover, since the first through fifth main ribs M1-M5 and
the first through ninth auxiliary ribs S1-S9 extend across the
opening 6 of the oil reservoir 4, it is possible to arrange the
first through fifth main ribs M1-M5 by effectively utilizing the
space in the opening 6 while hardly changing the outer shape of the
oil pan 1.
[0128] As described above, in the first embodiment, the ribs M1-M5
and S1-S9 in the oil reservoir 4 can increase rigidity of the oil
pan 1. In addition, since the fourth main rib M4, the second
auxiliary rib S2, and the first through fifth lower ribs L1-L5
divide the oil reservoir 4 into the main chamber P and the
sub-chamber Z, it is unnecessary to provide an additional oil pan
separator. Accordingly, the number of components of the engine can
be reduced, thereby reducing cost.
[0129] In addition, the presence of the first through fifth main
ribs M1-M5 and the auxiliary ribs S1-S9 in the oil reservoir 4 can
increase rigidity of the oil pan 1. Further, since the guide part
60 for guiding oil which has returned to the oil reservoir 4 to the
main chamber P is provided to be continuous to the ribs M1, S1, and
S2, the guide part 60 can be provided in the oil pan 1 by utilizing
the ribs M1, S1, and S2 without any additional structure for
providing the guide part 60 in the oil pan 1. Accordingly, the
configuration of the oil pan 1 including the guide part 60 can be
simplified.
[0130] Moreover, since the first main rib M1, the first auxiliary
rib S1, and the second auxiliary rib S2 can be joined together by
the guide part 60, rigidity of the oil pan 1 can be further
increased by utilizing the guide part 60.
[0131] Furthermore, since the oil pan 1 is divided into the upper
section 10 and the lower section 30, the upper section 10 and the
lower section 30 can be formed independently of each other.
Accordingly, even if the shape of the oil pan 1 is complicated, the
sections 10 and 30 can be easily feinted, and thus good formability
can be obtained, as compared to a case where the sections 10 and 30
are formed as one piece. The upper section 10 is reinforced by the
first through fifth main ribs M1-M5 and the first through ninth
auxiliary ribs S1-S9, and has its rigidity increased. The third
main rib M3 and the fourth auxiliary rib S4 of the upper section 10
having the thus-increased rigidity are joined to the element-fixing
rib 32 of the lower section 30, thereby firmly uniting the upper
section 10 and the lower section 30. At the same time, rigidity of
the lower section 30 can be enhanced, resulting in that rigidity of
the entire oil pan 1 made of resin to have light weight can be
increased.
[0132] The element-fixing rib 32 provided in the lower section 30
can increase rigidity of the lower section 30. Coupling the
element-fixing rib 32 and the lower section 30 can unite the upper
section 10 and the lower section 30 more firmly.
[0133] In addition, the oil strainer 5 can be formed as one piece
with the oil pan 1. The filter-element housing 17 of this oil
strainer 5 is constituted by the third main rib M3, the fourth
auxiliary rib S4, and the element-fixing rib 32. Accordingly, as
compared to a case where the filter-element housing 17 is made of
an additional member, the structure of the oil pan 1 can be
simplified, and the weight of the oil pan 1 can be reduced.
[0134] Further, since the first through fifth main ribs M1-M5
extend across the opening 6 of the oil reservoir 4 to join separate
portions of the peripheral wall 3 of the oil reservoir 4 together,
the ribs M1-M5 can sufficiently increase rigidity of portions near
the opening 6, which otherwise decreases easily, and vibration of
parts of the oil pan 1 can be reduced, thereby reducing noise.
Since the first through fifth ribs M1-M5 extend across the opening
6 of the oil reservoir 4 as described above, it is possible to
arrange the first through fifth main ribs M1-M5 by effectively
utilizing the space in the opening 6 while hardly changing the
outer shape of the oil pan 1. Accordingly, it is possible to
effectively arrange the first through fifth main ribs M1-M5 to
obtain high rigidity, while achieving a compact size of the oil pan
1 including the first through fifth main ribs M1-M5.
[0135] Since the first through fifth main ribs M1-M5 extend from
portions near the bolt-insertion holes Bf2-Bf4, Bb2-Bb4, B11, B12,
Br1, and Br2, strength of portions around the bolt-insertion holes
Bf2-Bf4, Bb2-Bb4, B11, B12, Br1, and Br2 can also be increased by
utilizing the first through fifth main ribs M1-M5.
[0136] In addition, since portions near the bolt-insertion holes
Bf2-Bf4, Bb2-Bb4, B11, B12, Br1, and Br2 are joined to each other
by the first through fifth main ribs M1-M5, strength of portions
near the bolt-insertion holes Bf2-Bf4, Bb2-Bb4, B11, B12, Br1, and
Br2 can be further increased.
[0137] Further, since the second, fourth, and fifth main ribs M2,
M4, and M5 joining portions near the bolt-insertion holes Bf3, Bb3,
B11, B12, Br1, and Br2 intersect each other, a force applied to,
for example, the second main rib M2 from the front to the rear is
distributed to the fourth main rib M4 and the fifth main rib M5.
Accordingly, deformation and damage of the oil pan 1 can be
reduced.
[0138] Further, since the first through fifth main ribs M1-M5 and
the first through ninth auxiliary ribs S1-S9 intersect each other
to form triangles in plan view, the structure of the oil pan 1 is
less likely to be deformed by a force applied to the side of the
peripheral wall 3, thereby further increasing rigidity.
[0139] Furthermore, the first, fourth, and fifth main ribs M1, M4,
and M5 are continuous to portions of the upper section 10
constituting the bottom wall 2, the bottom wall 2 and the
peripheral wall 3 can be joined together by the ribs M1, M4, and
M5, thereby further increasing rigidity of the oil reservoir 4.
[0140] Moreover, an oil pan 1 of an automobile can be hit by flying
stones from the front during driving in some cases. In this
embodiment, since the first through third main ribs M1-M3 extend in
the front-to-rear direction, an impact of the flying stones is
received by the first through third main ribs M1-M3, and thereby,
deformation and damage can be reduced.
[0141] In addition, since the first, fourth, and fifth main ribs
M1, M4, and M5, and the first, third, sixth, seventh, eighth, and
ninth auxiliary ribs S1, S3, S6, S7, S8, and S9 are continuous to
portions of the upper section 10 constituting the bottom wall 2,
rigidity of the bottom wall 2 can be increased. Accordingly, even
when a jack is fixed to the bottom wall 2 of the oil pan 1 to jack
up an automobile, deformation and damage of the bottom wall 2 can
be reduced.
[0142] In a case where a centrifugal force is produced during
driving of the automobile, the first through fifth lower ribs
L1-L5, the fourth main rib M4, and the second auxiliary rib S2, for
example, can reduce nonuniform distribution of oil in the oil pan
1. Consequently, it is possible to reduce sucking of air into the
oil pump.
[0143] The first through fifth main ribs M1-M5 and the first
through ninth auxiliary ribs S1-S9 may have notches or through
holes through which oil can be distributed.
[0144] In this embodiment, the oil pan 1 is formed by a combination
of the upper section 10 and the lower section 30. Alternatively,
the oil pan 1 may be formed as one piece.
[0145] The number of the first through fifth main ribs M1-M5 and
the first through ninth auxiliary ribs S1-S9 is not limited to the
above embodiment, and for example, no auxiliary ribs may be
provided. The first through fifth main ribs M1-M5 may have the same
thickness as that of the first through ninth auxiliary ribs S1-S9,
but may have thicknesses different from those of the first through
ninth auxiliary ribs S1-S9. The first through fifth main ribs M1-M5
and the first through ninth auxiliary ribs S1-S9 may be curved.
[0146] Any one of the first through fifth main ribs M1-M5 and the
first through ninth auxiliary ribs S1-S9 may be formed to be
continuous to the bottom wall 2. In this case, the rib continuous
to the bottom wall 2 may be formed as one piece with the bottom
wall 2, may be welded to the bottom wall 2, or may be bonded to the
bottom wall 2 with an adhesive.
[0147] Any one of the first through fifth main ribs M1-M5 and the
first through ninth auxiliary ribs S1-S9 may be bonded to the lower
section 30 by welding or with an adhesive.
[0148] Any one of the first through fifth lower ribs L1-L5 may be
bonded to the upper section 10 by welding or with an adhesive.
[0149] The first through fifth main ribs M1-M5 may be located at
positions separated from the bolt-insertion holes Bf1-Bf4. Bb1-Bb4,
B11, B12, Br1, and Br2.
[0150] In this embodiment, the oil strainer 5 is formed as one
piece with the oil pan 1. Alternatively, the oil strainer 5 and the
oil pan 1 may be formed as separate parts so that the oil strainer
5 is mounted to an engine independently of the oil pan 1.
Alternatively, the oil strainer may be mounted to the oil pan
1.
[0151] The fourth main rib M4 of the upper section 10 and the first
through third lower ribs L1-L3 of the lower section 30 may be
welded or bonded together. These ribs may be welded or bonded to
the second auxiliary rib 52 and the fifth lower rib L5, and may
also be welded or bonded to the upper section 10 and the fourth
lower rib L4 of the lower section 30.
[0152] As a first modified example illustrated in FIG. 18, a
through hole 65 for establishing communication between the main
chamber P and the sub-chamber Z may be formed in the bottom of the
second auxiliary rib S2. A through hole 66 for establishing
communication between the main chamber P and the sub-chamber Z may
be formed in the bottom of the fourth main rib M4. These through
holes 65 and 66 may be formed in intermediate portions, in the
vertical direction, of the ribs S2 and M4.
[0153] As a second modified example illustrated in FIG. 19, the
bottom wall of the tube portion 61 of the guide part 60 may extend
toward the oil strainer 5 so that return oil is caused to flow into
a portion near the suction hole 5a. With this configuration, the
temperature of oil to be sucked into the suction hole 5a after a
cold start can be further increased.
[0154] As a third modified example illustrated in FIG. 20, no tube
portion 61 is provided, and a through hole 67 formed in the second
auxiliary rib S2 and the guide plate portion 62 may constitute the
guide part 60. The upper edge of this through hole 67 is located
closer to the oil strainer 5 than the lower edge of the through
hole 67.
[0155] As in a fourth modified example illustrated in FIG. 21, the
oil strainer 5 and the oil reservoir 4 may be formed as separate
parts so that the oil strainer 5 is disposed in the main chamber P.
A discharge port 15a is formed in an upper portion of the oil
strainer 5, and a suction pipe 5c is formed in a lower portion of
the oil strainer 5. A suction port (not shown) is formed at the
bottom of the suction pipe 5c. Attachment flanges (fixing portions)
5b and 5b having fastening holes are formed at the periphery of the
oil strainer 5.
[0156] On the other hand, the fifth main rib M5 of the oil
reservoir 4 of the fourth modified example has a notch 77 having a
shape associated with the shape of the oil strainer 5. The fifth
main rib M5 has a fastening plate portion 78 to which one of the
attachment flanges 5b is engaged and fixed. The third main rib M3
has a fastening plate portion 79 to which the other attachment
flange 5b is engaged and fixed. The oil strainer 5 is attached to
the oil reservoir 4 by fixing the attachment flanges 5b and 5b to
the fastening plate portions 78 and 79 with a fastening material
(not shown). The oil strainer 5 may be attached to the oil
reservoir 4 by welding or with an adhesive, for example, without
using a fastening material.
Embodiment 2
[0157] FIGS. 22-24 illustrate a second embodiment of the present
invention. An oil pan 1 according to the second embodiment is
different from that of the first embodiment only in that the oil
strainer 5 is separated from the oil reservoir 4, and in the
structures of the ribs M1 through M4. Thus, in the following
description, the same reference numerals denote the same components
in the first embodiment, and only different aspects will be
described in detail.
[0158] Specifically, as illustrated in FIGS. 22 and 23, the oil pan
1 of the second embodiment includes first through fourth main ribs
M1 through M4. The first and second main ribs M1 and M2 are spaced
apart from each other, and extend substantially in parallel with
each other in the front-to-rear direction. The third and fourth
main ribs M3 and M4 are spaced apart from each other, and extend
substantially in parallel with each other in the right-to-left
direction. Intermediate portions of the first and second main ribs
M1 and M2 intersect intermediate portions of the third and fourth
main ribs M3 and M4. As also illustrated in FIG. 24, these
intersections of the ribs M1 through M4 form a rectangular
parallelepiped defining a main chamber P.
[0159] Portions of the first through fourth main ribs M1 through M4
defining the main chamber P form a projection wall 70 projecting
downward from the other portions. The projection wall 70 forms a
rectangular parallelepiped, and the bottom thereof is in contact
with a bottom wall 2. Four separate notches 70a, 70a, . . . are
formed in lower portions of the projection wall 70. Each of the
notches 70a extends upward from the lower edge of the projection
wall 70. The main chamber P communicates with a sub-chamber Z
through the notches 70a. The projection wall 70 may have a through
hole or a slit extending vertically.
[0160] Although not shown, the oil pan 1 also includes auxiliary
ribs as in the first embodiment.
[0161] A plate 71 extending substantially horizontally in the
drawing is disposed in the main chamber P. The plate 71 is located
at the middle, in the vertical direction, of the notches 70a, and
the periphery of the plate 71 is continuous to the inner surface of
the projection wall 70. The plate 71 serves as an inner wall of the
bottom of the main chamber P, and the bottom wall 2 serves as an
outer wall of the bottom of the main chamber P.
[0162] In the second embodiment, the bottom of the main chamber P
has a double structure made of the plate 71 and the bottom wall 2,
thereby enhancing heat insulating properties. Accordingly, in
particular, oil in the main chamber P is less likely to be cooled
by cold outside air in a cold state, and thus the temperature of
oil in the main chamber P can be increased quickly, thereby
reducing viscosity.
[0163] The oil strainer 5 indicated by virtual lines in FIG. 22 has
a cylindrical shape extending vertically, and is located in the
main chamber P. A suction port is formed in the bottom of the oil
strainer 5, and is located near the plate 71.
[0164] As described above, in the second embodiment, the first
through fourth main ribs M1 through M4 and the auxiliary ribs in
the oil reservoir 4 can increase rigidity of the oil pan 1. In
addition, the inside of the oil reservoir 4 is divided into the
main chamber P and the sub-chamber Z by the main ribs M1 through
M4. Accordingly, it is unnecessary to provide an additional oil pan
separator. As a result, the number of components of the engine can
be reduced, thereby reducing cost.
[0165] A heat insulator may be provided between the plate 71 and
the bottom wall 2.
[0166] In the foregoing examples of the first and second
embodiments, the oil pan 1 is divided into two. However, the
present invention is not limited to these examples, and the oil pan
1 may be divided into three or more. The direction of the division
of the oil pan 1 is not limited to the vertical direction, and may
be the front-to-rear direction or the right-to-left direction.
[0167] The oil pan 1 may be formed as one piece.
[0168] The present invention is applicable to oil pans for power
units such as various engines and automatic transmissions.
INDUSTRIAL APPLICABILITY
[0169] As described above, an oil pan according to the present
disclosure is suitable for attachment to an engine of an
automobile, for example.
* * * * *